This application claims priority to Taiwan Patent Application No. 091107047 entitled xe2x80x9cElevated Key Switch and Keyboard with the Elevated Key Switchxe2x80x9d, filed Apr. 9, 2002.
The present invention generally relates to an elevatable key switch and, more particularly, to a scissors-like elevatable key switch and a keyboard having the same.
Keyboards are widely used with various devices, such as computers, to input characters and numerals. To make a key on the keyboard easy to depress, the key is usually designed to function no matter where a force is exerted on the key cap. In other words, even though the force is exerted on the edge of the cap, the force is generally equally distributed over the entire surface of the cap with a scissors-like linkage. Furthermore, while space is an especially important consideration in designing keyboards of portable computing devices, key switches with scissors-like linkage are often the solution.
The height of key switches usually affects the size of a portable computing device and especially directly influences the thickness of a notebook computer. In order to reduce the overall thickness of a notebook computer, therefore, a common answer is to minimize the keystroke distance to reduce the height of key switches. However, the reduction of the keystroke distance also reduces the user""s sense of touch. Thus, reducing the height of key switches when a notebook is in closed storage configuration is another possible solution.
A conventional key switch of scissors-like linkage is disclosed in U.S. Pat. No. 5,793,605. As shown in FIG. 8A, scissors-like linkage 810 includes a joining plate 812, which depresses resilient dome 820 to activate the key switch 800. When the key switch 800 is not in use, the resilient dome 820 must move a distance relative to the scissors-like linkage 810, so that the key switch 800 collapses. However, the size of the resilient dome 820, which is relatively large, determines the required distance for the key switch 800 to collapse, as shown in FIG. 8B. Furthermore, the impact force of the scissors-like linkage is relatively large. If the joining plate 812 cannot equally distribute the force on the resilient dome 820, the resilient dome 820 is easily damaged.
Thus, there is a need to provide a key switch and a keyboard to eliminate problems of the prior art.
It is one aspect of the present invention to provide a key switch, which can selectively be in an operation configuration and a contraction configuration.
It is another aspect of the present invention to provide an elevatable key switch, which can collapse to reduce height of the key switch when the key switch is not in use.
It is a further aspect of the present invention to provide a key switch with a movable element, which maintains the impact of key cap in a uniform level.
In one embodiment, the present invention provides an elevatable key switch including a base, a cap, an up-down mechanism, an elastic member, a movable element, and a driving element. The cap is disposed above the base. The up-down mechanism, which is disposed between the base and the cap, supports the cap to perform vertical movement relative to the base. The elastic member is disposed on the base, and the movable element is movably disposed on the elastic member. The driving element drives the movable element to make substantial horizontal movement, so that the movable element selectively moves between a first position and a second position. When the movable element is in the first position, the movable element supports the up-down mechanism in an operation configuration. When the movable element is in the second position, the movable element releases the up-down mechanism entering a contraction configuration.
A collapsible keyboard including a casing and the elevatable key switch of the present invention is also provided. When the keyboard is not in use, the up-down mechanism is collapsed to enter a contraction configuration resulting in the reduction of height of the elevatable key switch.